Polyethylene terephthalate (PET) is a kind of polymer with excellent performance. PET is preferred because of its high modulus, high strength, crispness, good shape retention, safe and clean, and good barrier property. It is widely used in fiber industry, bottle packaging, film production and sheets materials, etc. The output production of PET is increasing year by year and its status in the industry has been significantly improved.
Industrial polyester fiber mainly refers to those used in industry, national defense, medical care, environmental protection and cutting-edge science. It is a kind of chemical fiber which has relatively special physical and chemical structure, properties and uses, or with special functions. The characteristics can be found in its resistance against strong corrosion, wearing, high temperature, radiation, fire, burning, high voltage current. It also has high strength and high modulus, and a variety of medical usage. The tent cloth using the high strength and low shrinkage polyester industrial filament has high peel strength and tear strength, which make the tent cloth suitable for various purposes, including flexible advertising light box materials, inflatable structural materials, tent-like buildings' fabric sunshade tent and so on. The high strength and, low shrinkage industrial yarn-based fabric materials are also applied in special protective clothing, camouflage, covering, backpack and other military supplements. As a kind of geotextile material with the advantages of light, soft, high strength, wear-resistant, corrosion-resistant, non-conductive, shock absorption and so on, it is also reliable and convenient to use. It can make our work more efficient, and will not damage the lifting objects. The expansion of industrial polyester fiber's applications has led the whole fiber industry to a more competitive edge in application areas. Polyester high-performance fibers are playing an increasingly important role in many aspects including reducing the weight of composite materials, durability in use and reducing maintenance costs and so on. In the next few decades, the development of high-performance polyester fiber is not only the progress of its amount, but also the development in the field of application and enhancement of the overall competitiveness of the industry chain to achieve substantial results.
High strength, high modulus, low shrinkage, dimensional stability, functionalization will be the main direction of the development of industrial polyester fiber. The fiber quality is related to the collection of polyester polymer structure, mainly related to the intermolecular force, crystal morphology and structure, orientation state structure, etc., and the shape and structure of the crystal is one of the key points. Polyester industrial yarn is widely used in different fields. For ultra-low shrinkage polyester industrial yarn, it has the characteristics of lower dry heat shrinkage and better dimensional stability. As a result, it is widely used in filter cloth, coated fabric, soft tube and belt latitude and so on.
Carboxyl end group, oligomer, and diethylene glycol (DEG) content are important quality indicators of polyester sections, in which oligomer and diethylene glycol are low molecular polymer. These reflect not only the quality of production status, but also affect the product quality after the spinning process. Therefore, reducing the carboxyl end groups, oligomers, diethylene glycol content in polyester sections play an important role in improving the quality of polyester products. The influence of carboxyl end groups on the performance of polymers cannot be ignored. Only by controlling the amount of polyester end carboxyl groups in the production, can we stabilize the uniformity of molecular weight distribution. The amount of diethylene glycol in the polyester sections is a very important quality index in polyester production. Because it has a direct impact on the melting point of polyester sections, the melting point of polyester sections will decline sharply with the increase of DEG content, so it not only reflects the quality of production, but also directly affects the post-processing and spinning process and silk quality. Oligomer in polyester is low molecular polymer with a degree of polymerization of less than 10 and can be classified into linear oligomers and cyclic oligomers, of which the majority are cyclic polymers, especially cyclic trimers. The oligomer is mainly influencing heterogeneous nucleation, spinning processing, the performance of polyester and after processing caused some adverse effects. Controlling the content of the three in polyester sections is a very important issue in the polyester production process.